Heretofore, as a fuel hose which is used in the fuel piping systems of automobiles and the like, a single-layer rubber hose comprising NBR . PVC rubber (a mixture of acrylonitrile-butadiene rubber and polyvinylchloride) superior in gasoline resistance and impermeability to gasoline has been well known. However, it is a current situation that such a single-layer hose cannot meet the recent severe regulations on impermeability to gasoline. In such a situation, to satisfy severer conditions, a hose comprising the above outer rubber layer and an inner fluoro rubber layer which is formed on the inside face of the outer rubber layer was developed and has been employed in some fields.
However, since the hose having the inner fluoro rubber layer has a defect of a high cost in spite of its excellent performance, such a hose has not been generally employed. In the meantime, it is proposed that the inner layer be formed by replacing the fluoro rubber with polyamide resin which is more inexpensive.
The polyamide resin has superior properties in gasoline resistance and impermeability to gasoline. However, since it shows a bad adhesive property with an outer rubber layer, it is required to apply adhesive on the inside face of the outer rubber layer to laminate these two layers. There causes a problem especially in a filler hose which functions to connect a hose end with the other material. Namely, the filler hose is often formed into a smooth faced and curved shape shown in FIG. 1 or into an accordion shape shown in FIG. 2 for wide adoptability. In case that a hose is formed into such a special shape, it is difficult to apply adhesive evenly on the inside face thereof and also a dry process after the application of the adhesive is required, resulting in a more complicated process. Further, there is the anxiety that adhesive solvent may aggravate environment. Therefore, it is strongly demanded to establish a method of producing an inexpensive fuel hose easily by laminating the inner polyamide resin layer on the inside face of the outer rubber layer without applying adhesive therebetween.